Function.prototype.myBind = function (context, ...args1) {
  return function (...args2) {
    context = context || window;
    context = Object(context);
    let key = Symbol("key");
    context[key] = this;
    let res = context[key](...args1, ...args2);
    Reflect.deleteProperty(context, key);
    return res;
  };
};
